Mains water is now regulated at a maximum of 500 kPa for new homes. Recycled water is delivered at a bit less than this.

If pressure for garden watering is a concern, just buy an 18 mm hose and join a short length of 12 mm garden hose to the end so that you can still use the standard 12 mm hose connections. This will substantially reduce friction loss and deliver plenty of pressure.

Cisterns are regulated to fill at 6+ lpm. There will be plenty of pressure for this.